JPH1097120A - Electric discharge wire fixing mechanism for corona discharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely fit an electric discharge wire and to reduce a cost for maintenance by providing a fixing pin with an insertion part which can be press-fitted into the through-hole of a wire fixing member and interposing one end of the electric discharge wire together with the wire fixing member. SOLUTION: The fixing pin 33 is provided with the cylindrical insertion part 41 engaged with the through-hole 39 and a guide groove 42 for guiding the electric discharge wire is formed on the tip of the insertion part 41. Then, the pin 33 is forcefitted into the hole 39 of the wire fixing member 38 together with the electric discharge wire while guiding one end of the electric discharge wire by the groove 42. One end of the electric discharge wire is interposed by the fixing member 38 and the pin 33. When the pin 33 is damaged because it is deteriorated, the fixing member 38 is taken out from a supporting part and the pin 33 is pushed out from an aperture on the opposite side of the hole 39. Thus, since the fixing member 38 can be used again by exchanging only the pin 33, the cost for maintenance is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge wire fixing mechanism, and more particularly, to a corona discharge device in which an insulative end block is provided at both ends of a conductive chassis and a corona discharge wire is stretched between the end blocks. The present invention relates to a discharge wire fixing mechanism for electric appliances.

[0002]

2. Description of the Related Art Generally, in a copying machine or the like, an electrostatic latent image corresponding to image information of a document is formed on a photosensitive member, and this electrostatic latent image is visualized by a developing device to form a toner image. The toner image is transferred and the image information of the document is copied onto paper. In order to form an electrostatic latent image on the photoreceptor, a process for charging the photoreceptor surface to a constant potential is required as a pre-step. As this charging process,
A method using corona discharge (hereinafter, referred to as corona charging) is generally used.

A corona discharger used for corona charging is:
It has a shield case, a pair of insulating end blocks supported on both ends of the shield case, and a discharge wire stretched inside the shield case. One end of the discharge wire is fixed to one of the end blocks via a spring,
The other end is fixed to the other end block, and is tensioned by a biasing force of a spring.

In order to fix a discharge wire in such a corona discharger, for example, Japanese Utility Model Laid-Open Publication No. 63-15514
The structure disclosed in Japanese Patent Publication No. 6 is used. Here, a fitting recess is provided in the end block at the end of the shield case, and the discharge wire is locked by a locking member fitted in the fitting recess. The locking member uses a fixing pin formed in a screw shape having a body and a head, and a guide having a predetermined width for guiding the discharge wire is formed on the tip side of the body, and the upper part thereof is In addition, a holding portion having a gap smaller than the width of the guide portion is formed.

[0005] In this structure, the discharge wire is guided by the guide portion and is held by the holding portion. Then, in this state, the end of the discharge wire is fixed by pressing the fixing pin into the fitting concave portion.

[0006]

In the above-described corona discharger, the end block and the fixing pin are often formed of an elastic synthetic resin material in order to sandwich the discharge wire. Since a high voltage is applied to the discharge wire, it is inevitable that end blocks and fixing pins that hold the discharge wire are deteriorated. In particular, if the fixing pin is broken at the time of replacement of the discharge wire during maintenance, a part of the fixing pin remains in the fitting concave portion of the end block, and it becomes difficult to remove the fixing pin. For this reason, it is necessary to replace the end block or the corona discharger itself, which may increase maintenance costs.

In order to prevent the end block from being deteriorated due to the high voltage applied to the discharge wire, it is necessary to prevent the end block from deteriorating.
As shown in JP-A-6961 and JP-A-2-95039, it is conceivable that the end block is made of a ceramic material. However, in this case as well, the fixing pin must be formed of a material such as synthetic resin having elasticity due to the necessity of holding the discharge wire, and the above-described problem still remains. Also, since the end block is made of a ceramic material, it is difficult to reduce the manufacturing cost. If a part of the broken fixing pin remains and the end block needs to be replaced, the maintenance cost is further increased. The problem of rising occurs.

An object of the present invention is to provide a corona discharger,
An object of the present invention is to make it possible to easily and surely attach a discharge wire and to reduce maintenance costs.

[0009]

SUMMARY OF THE INVENTION The present invention provides a discharge wire fixing mechanism for a corona discharger in which insulating end blocks are provided at both ends of a conductive chassis, and a corona discharge wire is stretched between the end blocks. And a supporting portion, a wire fixing member, and a fixing pin. The support is provided on the end block. The wire fixing member is detachably attachable to the support portion, and is formed in a cylindrical shape having a through hole. The fixing pin has an insertion portion that can be pressed into the through hole of the wire fixing member, and clamps one end of the discharge wire together with the wire fixing member.

[0010] In this case, the wire fixing member is mounted on the support of the end block, and the fixing pin is inserted into the through hole together with the discharge wire to fix the discharge wire. If the fixing pin is deteriorated and damaged, and a part remains in the through hole of the wire fixing member, remove the wire fixing member from the support portion,
It can be extruded from the opening opposite to the through hole. Therefore, by replacing only the fixing pin, the wire fixing member can be used again, and the maintenance cost can be reduced.

Here, the fixing pin can be made of a hard synthetic resin, and the wire fixing member can be made of ceramics. In this case, the life of the wire fixing member can be extended, and the discharge wire can be stably fixed.

[0012]

FIG. 1 shows a copying machine having a corona discharger according to an embodiment of the present invention. In the figure, a document table 2 is fixed on the upper surface of a copying machine body 1. A document holder 3 is mounted on the document table 2 so as to be openable and closable. On the other hand, on the right side of the copying machine body 1,
Paper cassettes 5 and 6 are detachably mounted, and a discharge tray 7 for discharging copied paper is mounted on the left side.

Inside the copying machine main body 1, an optical system 8 for reading a document is provided at an upper portion thereof. A photosensitive drum 9 is arranged at substantially the center of the apparatus main body 1. Around the photoconductor drum 9, a main charging corona discharger 10, a developing device 11, a transfer corona discharger 12, a separation corona discharger 13, and a cleaning device 14 for charging the photoconductor drum 9 to a predetermined charge are provided. Are located.

Further, between the image forming unit formed by the photosensitive drum 9 and the like and the paper feeding cassettes 5 and 6, a paper feeding device 15 for conveying paper to the image forming unit is provided. Further, a sheet conveying device 16 is provided downstream of the image forming section. A fixing device 20 for fixing the toner image on the conveyed paper is provided between the paper conveyance device 16 and the discharge roller 19.

As shown in FIG. 2, the corona discharger 10 for main charging includes a shield case 21, a pair of first and second insulating end blocks 22, 23, and a shield case 2.
1 and a discharge wire 24 stretched inside. The shield case 21 has a U-shaped cross section, and extends along the axial direction of the photosensitive drum 9. Discharge wires 24 are stretched in a space 25 of the shield case 21, and end blocks 22 and 23 are supported at both ends. Both end blocks 22 and 23 are formed in a box shape having an open upper part, and cutouts 22a and 23a through which the discharge wire 24 passes are formed on opposing side walls. A boss 27 for mounting the discharge wire 24 is formed in the recess 26 of the first end block 22. One end of the discharge wire 24 is locked to the boss 27 via a tension adjusting spring 28. In the recess 30 of the second end block 23, a discharge wire fixing mechanism according to one embodiment of the present invention is provided.

As shown in FIG. 3, a boss 32 is formed in the recess 30 of the second end block 23. The boss 32 has a substantially cylindrical shape, and has a fitting recess 34 at the center.
Is provided. In addition, around the fitting recess 34, approximately L
A letter-shaped notch 35 is provided. Notch 35
The guide portion 3 extends downward from the upper edge of the boss portion 32.
6 and a locking portion 37 extending from the lower end of the guide portion 36 to one side in the horizontal direction. The boss portion 32 is formed integrally with the end block 23 using an elastic synthetic resin having elasticity.

A wire fixing member 38 is mounted in the fitting recess 34 of the boss 32. This wire fixing member 38
It has a cylindrical shape made of a ceramic material and has a through hole 39 at the center. A positioning projection 40 is provided on the outer peripheral surface of the wire fixing member 38 at a position corresponding to the notch 35 of the boss 32. Positioning projection 40
When the wire fixing member 38 is mounted in the fitting recess 34 of the boss portion 32, the wire fixing member 38 is guided to the lower end position of the guide portion 36 of the cutout portion 35, and the wire fixing member 38 is rotated in the horizontal direction. With this, it is locked to the locking portion 37.

The fixing pin 33 is pressed into the through hole 39 of the wire fixing member 38. The fixing pin 33 has a through hole 39.
And a guide groove 42 for guiding the discharge wire at the end of the insertion portion 41.
Are formed. At the top of the insertion section 41, the insertion section 41
A column-shaped head 43 having a larger diameter than that is provided. The head 43 is configured to have substantially the same diameter as the outer circumference of the wire fixing member 38. The fixing pin is pressed into the through hole 39 of the wire fixing member 38 together with the discharge wire while guiding one end of the discharge wire by the guide groove 42. As a result, one end of the discharge wire is sandwiched between the wire fixing member 38 and the fixing pin 33.

Next, the operation of attaching and detaching the discharge wire will be described. First, the wire fixing member 38 is mounted on the boss 32 of the end block 23. At this time, the wire fixing member 38
Is guided by the guide portion 36 of the notch 35. After the positioning protrusion 40 reaches the lower end of the guide portion 36 of the notch 35, the wire fixing member 38 is rotated so that the positioning protrusion 40 is located at the locking portion 37.

When attaching the discharge wire 24, one end of the discharge wire 24 is attached to a spring 28, and this spring 28
Is fixed to the boss 27 of the insulating block 22. Then, the discharge wire 24 is connected to the notches 22a of the insulating blocks 22 and 23,
Through the wire 23 a, it is stored in the wire storage space 25 of the shield case 21. Next, the other end of the discharge wire 24 is locked in the guide groove 42 of the fixing pin 33, and in this state, the insertion portion 41 is inserted.
Is engaged with the through hole 39. The discharge wire 24 is sandwiched between the outer peripheral surface of the insertion portion 41 of the fixing pin 33, the inner peripheral surface of the through hole 39 of the wire fixing member 38, the lower surface of the head 43 of the fixing pin 33, and the upper surface of the wire fixing member 38, and is securely mounted. .

When the fixing pin 33 is deteriorated, the head 43 and the insertion portion 41 are separated from each other, and when the insertion portion 41 remains in the through hole 39 of the wire fixing member 38, the wire fixing member 38 is rotated. The positioning projection 40 and the notch 3
5 is released from the locking portion 37, and the wire fixing member 38 is removed from the end block 23. Thereafter, by pushing out the insertion part 41 that has been broken off from the opening on the opposite side of the through hole 39, the wire fixing part 38 can be used again.

According to this embodiment, even if the fixing pin 33 is broken, it is easy to remove the fixing pin 33 from the wire fixing member 38. It can be used and maintenance costs can be reduced. Further, the wire fixing member 38 is made of a ceramic material, and can be prevented from deteriorating and have a long life.

[Other Embodiments] Notch 35 of Boss 32
The wire fixing member 38 and the positioning protrusion 40 of the wire fixing member 38 may be omitted, and the wire fixing member 38 may be press-fitted into the fitting recess 34 of the boss 32. Also, the wire fixing member 38
It is also possible to form a screw thread in the fitting recess 34 so as to screw together.

[0024]

According to the present invention, when the fixing pin is deteriorated and damaged and a part thereof remains in the through hole of the wire fixing member, the wire fixing member is removed from the supporting portion, and the fixing pin is opposite to the through hole. It can be extruded from the side opening. Therefore, by replacing only the fixing pin, the wire fixing member can be used again, and the maintenance cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic vertical cross-sectional view of a copier to which an embodiment of the present invention is applied.

FIG. 2 is a partially exploded perspective view of a corona discharger provided in the copying machine.

FIG. 3 is a perspective view of a discharge wire fixing mechanism according to an embodiment of the present invention.

FIG. 4 is a sectional view of the fixing mechanism.

[Explanation of symbols]

 24 Discharge wire 32 Boss 33 Fixing pin 34 Fitting recess 35 Notch 38 Wire fixing member 39 Through hole 40 Positioning protrusion 41 Insertion part 42 Guide groove 43 Head

Claims (3)

[Claims] 1. A discharge wire fixing mechanism for a corona discharger in which insulating end blocks are provided at both ends of a conductive chassis, and a corona discharge wire is stretched between the end blocks. A support portion provided on the support portion, a tubular wire fixing member detachably attachable to the support portion, having a through hole, and an insertion portion press-fittable into the through hole of the wire fixing member, the wire A discharge wire fixing mechanism for a corona discharger, comprising: a fixing member for holding one end of the discharge wire together with a fixing member. 2. A discharge wire fixing mechanism for a corona discharger according to claim 1, wherein said fixing pin is made of a hard synthetic resin. 3. A discharge wire fixing mechanism for a corona discharger according to claim 1, wherein said wire fixing member is made of ceramic.